This is a long but thorough explanation of the history and Theological meaning of the Filioque:
catholic-legate.com/apologetics/thechurch/articles/filioque.aspx
It goes into the context surrounding the teaching as well as what the Eastern Fathers taught regarding the relationship between the Son and the Holy Spirit. It shows the language differences between the Latin Fathers and the Greek Fathers. It also distinguishes between the different Trinitarian analogies (the Monarchy of the Father, the Collective Sense of Procession, etc) and what the context is when dealing with the procession of the Holy Spirit.
The West used the Filioque and maintained Communion with the East for quite some time. There is plenty from St Cyril of Alexandria that shows that the earlier Eastern Fathers were not so opposed to the idea behind the Filioque as they were opposed to its being unilaterally added to the Creed. Here are two of many examples from St Cyril:
When then “He,” that is the Comforter, the Spirit of Truth, is come, He shall guide you into all the truth. See how free from extravagance the expression is: note the soberness of the phrase. For having told them that the Comforter would come unto them, He called Him the Spirit of Truth, that is, His own Spirit. For He is the Truth. For that His disciples might know that He does not promise them the visitation of a foreign and strange power, but rather that He will vouchsafe unto them His Presence in another form, He calls the Comforter the Spirit of Truth, that is, His own Spirit.
For the Holy Spirit is not in truth alien from the Substance of the Only-begotten, but proceeds naturally from it, having no separate existence from Him so far as identity of nature is concerned, even though He may be in some sort conceived of as having a separate existence. The Spirit of Truth then, He says, will lead you to complete knowledge of the truth. For as having perfect knowledge of the truth, of which He is also the Spirit, He will make no partial revelation of it to those who worship Him, but will rather engraft in their hearts the mystery concerning it in its entirety. For even if now we know in part, as Paul says, still, though our knowledge be limited, the fair vision of the truth has gleamed upon us entire and undefiled. As then no man knoweth the things of a man, according to the Scripture, save the spirit of the man which is in him, in the same way, I think, to use the words of Paul, none knoweth the things of God save the Spirit of God which is in Him.
- St Cyril of Alexandria, Homilies on the Gospel of John, Book 10
For that the Spirit impresses the Saviour’s Image on the hearts of those who receive Him surely does not admit of question; for Paul plainly exhorteth those who had fallen through weakness into observance of the Law, in the words: My little children, of whom I am again in travail until Christ be formed in you. For he says that Christ will not be formed in them save by partaking of the Holy Spirit, and living according to the law of the Gospel. Therefore, as in the firstfruits of creation, which is made regenerate into incorruption and glory and into the Image of God, Christ establishes anew His own Spirit in His disciples. For it was necessary that we should also perceive this truth, namely, that He brings down and grants the Spirit unto us.
Therefore, also, He said: All things, whatsoever the Father hath, are Mine. And as the Father hath, of Himself and in Himself, His own Spirit, so also the Son hath the Spirit in Himself, because He is Consubstantial with Him, and essentially proceeded from Him, having by Nature in Himself all the attributes of His Father.
- St Cyril of Alexandria, Homilies on the Gospel of John, Book 12